The invention deals generally with a disassembling apparatus and more specifically with an apparatus for removing salvageable end slats from wooden pallets.
Almost everyone is familiar with the common wooden pallet. It is a low height, open ended, box-like structure which is used to support loads above floor level so that they can be moved easily without any special effort to get the loads onto a wheeled vehicle. The typical pallet has two layers of separated flat, parallel slats, with the two layers of slats attached to and separated by three "stringers". The slats are usually nailed to the stringers, and the stringers run perpendicular to the slats and are located at the sides and in the center of the pallet. The stringers are typically four to six inches high so that the forks of a towmotor vehicle or a pallet truck can be placed between the layers of slats to lift a load placed on the top layer of slats.
It is not surprising to learn that pallets suffer considerable damage in their normal use. The forces applied to them by powerful towmotor vehicles and by overhanging loads can particularly damage the end slats whose edges are exposed to contact with the vehicle. The other components of a pallet, the stringers and the inner slats, are, however, much less likely to suffer damage. What is not so apparent about pallets is that they have a significant cost of manufacture, and that it is economically advantageous to repair those with damaged end slats, rather than to discard a whole pallet.
Furthermore, even though it can be beneficial to repair or replace the end slats using even simple hand tools, it is substantially cheaper to do so when a machine is available to remove the end slats quickly. At least one such machine has been patented. U.S. Pat No. 4,285,110 by Fagre describes such a device. It operates upon a pallet resting on a flat table surface by locating an end slat within a slot formed of multiple fingers, and then pivoting the slot 90 degrees until it is directly above the pallet so that the slat is pulled from the stringers and falls down on the pallet.
It is particularly noteworthy that, when the action to move the slat begins, the pallet also is moved until it slams into a fixed pallet stop to prevent further motion. This impact of the pallet hitting the stop can cause severe damage to both the slat being removed and the other components of the pallet. The slat being removed is frequently broken or otherwise damaged by the force of the narrow fingers lifting the slat when the pallet is suddenly impacted against the pallet stop. Nevertheless, this pallet movement and the violent impact with the stop has been considered an effect of such machines which can not be escaped. Since pallets are not precision made assemblies, and there is no requirement to make them as such, it is not unusual to have rather large variations in the heights of the pallets which are encountered by a disassembly machine. Thus, if a machine is built to minimize the movement of the pallet by locating the fixed pallet stop so that it has a close clearance with one pallet, there is a good chance that the pallet stop will prevent another somewhat higher pallet from being loaded into the machine. On the other hand, if the pallet stop is located to permit clearance with the highest possible pallet, the pallets with less height will be slammed against the pallet stop when the machine operates to separate a slat from the stringers.
The pallet disassembly machine of the present invention solves this dilemma and furnishes a machine which removes the end slats without substantial additional damage to the slats. The present invention thereby makes many of the slats which are removed from the pallets available for reuse.